Help - blotches!

[bigstick]

Can anyone help me with this? I have blotches on either side of the image and I have no idea what to do to get rid of them.

The scene is for the First Floor stair lobby of a new Primary School and is lit by a spotlight for the sun with several area lights in the fittings.

My settings are:-

Photon mapping with irradiance caching
Area lights computed separately
Light mapping 600k photons received, N=800

Precahche steps 3, Autophotons low 20%, high 80%

Precache dist 50%, Precache blur 400%, Photons multiplier 2

FG rays 50 min, 600 max, threshold 0.0001
FG distance min 20%, dist max 300%
FG angle tolerance 20deg, spatial tolerance 0.1, B/D 10%

Rays Min 10, Rays max 60, GI resolution 1m

Tailer- recurse 10;prerender 1,2,0.1;gradients_neighbour 0.1;limitdr -1;

I confess to only having a very slight understanding of the render settings. I read all the posts and tips, and try to learn from other people's setups. It gets me results, but occasionally I get problems like this.

If anyone has any suggestions, I would be really grateful.

[jure]

Can you show the precomputed unfiltered render please? I suspect you're not receiving enough photons on those parts.

[bigstick]

Here it is, I can't see a particular problem, but then I'm no expert

[jure]

Hmm it doesn't look like there is photon problem.
But you can try increase autophotons steps to 4 or more. Also render without materials, just a white version so we can see error better (you can use override color).

[bigstick]

Actually I'm not sure how to use the override colour feature. It doesn't work quite the same way for me. I have e-mailed GT about it.

[jure]

You just enable it and choose a color... Anyways you can make all your surfaces gray or some light color and will get the same effect.

[jure]

Oh it looks like this thread was locked again accidentally...

[bigstick]

Sorry for the delay, Grzegorz needs to make some changes before I can use the colour override. I'm sure it won't be long though.